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  C Programming Tutorials
Basics of C:
Facts about C
Why to Use C
C Program File
C Compilers

Program Structure:
Simple C Program
C Program Compilation

Basic DataTypes:

Variable Types:
Local Variable
Global Variable

Storage Classes:
auto storage class
register storage class
static storage class
extern storage class

Using Constants:
Defining Constants
The enum Data Types

Operator Types:
Arithmetic Operators
Logical Operators
Bitwise Operators
Assignment Operators
Misc Operators

Control Statements:

Input and Output:
printf() function
scanf() function

Pointing to Data:
Pointers and Arrays
Pointer Arithmetic
Pointer Arithmetic with arrays

Using functions
Declaration and Definition

Reading and Writing Strings
String Manipulation Function

Structured DataTypes:
Pointer to Structure

Working with Files:
Basic I/O

Bits Manipulation
Bits Field

Pre-Processors Examples
Parameterized Macros
Macro Caveats

Useful Concepts

Built-in Library Functions:
String Manipulation Function
Memory Management Function
Buffer Manipulation
Character Functions
Error Handling Functions

Soft Skills
Communication Skills
Leadership Skills




C Programming Tutorials

Program Structure
A C program basically has the following form:

  • Preprocessor Commands

  • Functions

  • Variables

  • Statements & Expressions

  • Comments

The following program is written in the C programming language. Open a text file hello.c using vi editor and put the following lines inside that file.

#include <stdio.h>

int main()
/* My first program */
printf("Hello, TechPreparation! \n");

return 0;

Preprocessor Commands:
These commands tells the compiler to do preprocessing before doing actual compilation. Like #include <stdio.h> is a preprocessor command which tells a C compiler to include stdio.h file before going to actual compilation. You will learn more about C Preprocessors in C Preprocessors session.

Functions are main building blocks of any C Program. Every C Program will have one or more functions and there is one mandatory function which is called main() function. This function is prefixed with keyword int which means this function returns an integer value when it exits. This integer value is returned using return statement.

The C Programming language provides a set of built-in functions. In the above example printf() is a C built-in function which is used to print anything on the screen.

Variables are used to hold numbers, strings and complex data for manipulation. You will learn in detail about variables in C Variable Types.

Statements & Expressions :
Expressions combine variables and constants to create new values. Statements are expressions, assignments, function calls, or control flow statements which make up C programs.

Comments are used to give additional useful information inside a C Program. All the comments will be put inside /*...*/ as given in the example above. A comment can span through multiple lines.

Note the followings

  • C is a case sensitive programming language. It means in C printf and Printf will have different meanings.

  • C has a free-form line structure. End of each C statement must be marked with a semicolon.

  • Multiple statements can be one the same line.

  • White Spaces (ie tab space and space bar ) are ignored.

  • Statements can continue over multiple lines.

C Program Compilation
To compile a C program you would have to Compiler name and program files name. Assuming your compiler's name is cc and program file name is hello.c, give following command at Unix prompt.

$cc hello.c

This will produce a binary file called a.out and an object file hello.o in your current directory. Here a.out is your first program which you will run at Unix prompt like any other system program. If you don't like the name a.out then you can produce a binary file with your own name by using -o option while compiling C program. See an example below

$cc -o hello hello.c

Now you will get a binary with name hello. Execute this program at Unix prompt but before executing / running this program make sure that it has execute permission set. If you don't know what is execute permission then just follow these two steps

$chmod 755 hello

This will produce following result
Hello, TechPreparation!

Congratulations!! you have written your first program in "C". Now believe me its not difficult to learn "C".

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